Electrically-actuated artificial muscle fiber with bidirectional linear strain and preparation method thereof
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Solution Overview
Problem
Current artificial muscle fibers are limited by single active actuation mode and low actuation strain, restricting their application and development, as they can only actuate in one direction under voltage and return to initial length passively due to material elasticity, with low strain values.
Innovation Solution
An electrically-actuated artificial muscle fiber with bidirectional linear strain is developed, utilizing a helical structure with electrode and insulating layers, enabling active elongation and contraction under electric field stimulation, and featuring electrical self-healing properties, allowing for higher frequency response and broader application.
Engineering Contradictions & Design Principles
Engineering Contradiction Analysis
1Ease of manufacture
If polymer fiber twisting technology is used to create artificial muscle fibers, then the fibers can generate torsional and linear locomotions with simple realization, but the actuation frequency is limited to low values (0.01-10 Hz) due to ion diffusion rate or cooling rate limitations
Solution Approach 1:
The patent replaces thermal actuation mechanisms with electrostatic actuation. Instead of relying on heat-driven ion diffusion or cooling processes that limit frequency, the invention uses electric fields to directly actuate dielectric elastomer fibers through Maxwell stress, enabling high-frequency operation (1-100 Hz) while maintaining manufacturing simplicity
Solution Approach 2:
The patent changes the actuation parameter from thermal (temperature) to electrical (voltage). By applying high voltage to dielectric elastomer fibers, the material undergoes rapid electrostatic deformation without thermal lag, fundamentally increasing the actuation frequency from 0.01-10 Hz to 1-100 Hz while keeping the fiber structure manufacturable
2Productivity
If dielectric elastomer fibers are used to achieve high actuation frequency, then the actuation frequency increases to 1-100 Hz, but the fibers can only be actively actuated in a single direction under applied voltage and passively restore to initial length after voltage removal, limiting application range
Solution Approach 1:
The patent introduces asymmetric structural design by winding dielectric elastomer films into helical or coiled configurations. This asymmetric geometry enables the fiber to exhibit different mechanical responses during expansion and contraction phases under alternating voltage, achieving bidirectional active actuation capability while maintaining high frequency operation
Solution Approach 2:
The patent implements dynamic structural transformation where the fiber can switch between different actuation modes (contraction, expansion, torsion) by changing the applied voltage waveform and frequency. The dynamic reconfiguration of the helical structure under alternating voltage enables versatile bidirectional locomotion beyond simple unidirectional contraction
3Device complexity
If linear morphology fibers are used, then the structure is simple, but the actuation strain value is relatively low (about 3% at 8 KV voltage)
Solution Approach 1:
The patent transforms the linear fiber morphology into curved helical or coiled structures. This curvature amplification mechanism converts small radial expansions of the dielectric elastomer into large axial elongations of the fiber, achieving high actuation strain (exceeding 3%) while maintaining relatively simple device structure
Solution Approach 2:
The patent exploits dimensional transformation by applying voltage radially to the dielectric elastomer film, which then translates into axial motion through the helical geometry. This cross-dimensional actuation mechanism converts radial electric field effects into amplified axial strain output
Applied Scientific Principles
This section explains which scientific principles are used to turn an abstract innovation direction into a practical engineering solution.
Function Achieved in This Case
The fiber achieves significant actuation strain and stability, with the ability to repeatedly actuate at high frequency without degradation, suitable for advanced robotics and prosthetics, and resistant to high-voltage breakdown.
Implementation Method 1
under the Maxwell stress of electric field, the fiber sheath compressed to realize the active actuation of axial elongation
Implementation Method 2
The upper layer and the lower layer of fiber matrix are covered with one electrode layer respectively... The helical fiber body is formed by winding
Data Source
AI summary
An electrically-actuated artificial muscle fiber with bidirectional linear strain and a preparation method thereof are provided. The artificial muscle fiber includes a fiber matrix, electrode layers and insulating layers. The artificial muscle fiber takes the fiber matrix as a skeleton, upper and lower layers of the fiber matrix are covered with one electrode layer respectively, and one insulating layer is covered on a surface of each of electrode layers. A helical fiber body is formed by winding. Finally, the artificial muscle fiber is formed through packaging, where metal wires are taken as leads and respectively connected to upper and lower layers of electrodes.